Cisco predicts that the number of network-connected devices will be more than 15 billion, twice the world's population, by 2015. In its Visual Networking Index (VNI) Forecast (2010-2015) report released today, the company also predicts the total amount of global Internet traffic to quadruple by 2015 and reach 966 exabytes per year.

The projected increase of Internet traffic between 2014 and 2015 alone is 200 exabytes, according to VNI — greater than the total amount of Internet Protocol traffic generated globally in 2010. "On the verge of reaching 1 zettabyte, which is equal to a sextillion bytes, or a trillion gigabytes by 2015, global IP traffic growth is driven by four primary factors," according to Cisco. These primary factors are specified as:

1. An increasing number of devices: The proliferation of tablets, mobile phones, connected appliances and other smart machines is driving up the demand for connectivity. By 2015, there will be nearly 15 billion network connections via devices — including machine-to-machine — and more than two connections for each person on earth.

2. More Internet users: By 2015, there will be nearly 3 billion Internet users --more than 40 percent of the world's projected population.

3. Faster broadband speed: The average fixed broadband speed is expected to increase four-fold, from 7 megabits per second in 2010 to 28 Mbps in 2015. The average broadband speed has already doubled within the past year from 3.5 Mbps to 7 Mbps.

4. More video: By 2015, 1 million video minutes --the equivalent of 674 days --will traverse the Internet every second.

Additional study highlights:

Total Global IP Traffic in "Bytes"

Global IP traffic is expected to reach 80.5 exabytes per month by 2015, up from approximately 20.2 exabytes per month in 2010.

Average global IP traffic in 2015 will reach 245 terabytes per second, equivalent to 200 million people streaming an HD movie (1.2 Mbps) simultaneously every day.

Regional IP Traffic Trends

By 2015, the Asia Pacific region will generate the most IP traffic (24.1 exabytes per month), surpassing last year's leader, North America (22.3 exabytes per month), for the top spot.

The fastest-growing IP-traffic regions for the forecast period (2010 — 2015) are the Middle East and Africa (which had a 52-percent compound annual growth rate, for an eightfold growth), surpassing last year's leader Latin America (48 percent CAGR, sevenfold growth).

Primary Growth Driver: Consumer Video

The global online video community will increase by approximately 500 million users by 2015, up from more than 1 billion Internet video users in 2010.

Global Device Growth

In 2010, PCs generated 97 percent of consumer Internet traffic. This will fall to 87 percent by 2015, demonstrating the impact that devices like tablets, smartphones and connected TVs are having on how consumers access and use the Internet.

Accessing the Internet on Web-enabled TVs continues to grow and by 2015, 10 percent of global consumer Internet traffic and 18 percent of Internet video traffic will be consumed via TVs.

3DTV and HD (Advanced Video)

Global advanced video traffic, including three-dimensional (3-D) and high-definition TV (HDTV), is projected to increase 14 times between 2010 and 2015.